Means for sweeping pressure mines



L. F. JONES Sept. 12, 1967 MEANS FOR SWEEPING PRESSURE MINES 2 Sheets-Sheet Filed June 28, 1966 INVENTOR LOUIS F. JONES III 4ll| I ATTORNEY v Sept. 12, 1967 I L. F. JoNEs 3,340,843

' n MEANS FOR SWEEPING PRESSURE MINES 'Fi-led June 28, 1966 2 Sheets-5heet K '8 2l I ll Il 7 INVENTOR Lou s F. .JONES s BSBYMM ATTORNEY United States Patent O 3,340,843 MEANS FOR SWEEPING PRESSURE MINES Louis Franklin Jones, Rte. 3, Box 4350, Panama City, Fla. 32401 Filed June 28, 1966, Ser. No. 561,141 7 Claims. (Cl. 114-68) ABSTRACT OF THE DISCLOSURE A naval minesweeper detonates pressure mines located in a body of water by creating a signature pressure equivalent to that caused by a vessel which the mine is designed to destroy. The minesweeper is fabricated of an open truss structure of interconnected tubular members. Buoyant means are provided for oating the structure in a body of Water. Panel sections cover recessed sides of the truss structure where it extends below the water surface. The panel sections are hinged like cafe doors and resiliently biased to a closed position. By these means there is simulated the physical shape of a target vessel. This makes it possible for the structure to endure proximate mine explosions. The tubular members are internally interconnected and filled with a liquid to increase shock resistance.

This invention relates to naval mine sweepers and it is more particularly concerned with a mine sweeper which functions to detonate pressure mines located in a body of water by creating a signature pressure equivalent to that caused by a vessel which the mine is designed to destroy.

The general object of the invention is the provision of means for detonating a series of naval mines of the type mentioned in a continuous operation with minimal damage to the mine sweeper.

Pressure mines are triggered by some predetermined variation in the ambient hydrostatic pressure. When a vessel passes through the body of water, a pressure drop occurs in the pressure head of the water below and surrounding it. This is due to a law of fluid motion known as Bernoullis law by which fluid pressure is known to vary inversely with the velocity. In the case of a vessel passing through water, the effect is the same as if the vessel were motionless yand the water were moving in relation to it. This known fact is usedinthe design of pressure naval mines to furnish a signature pressure for detonating the mine.

Accordingly, a specific object is the provision of a structure which can be moved through water and which has physical ch-aracteristics similar to that of a vessel which a submerged pressure mine is designed to destroy but which is highly invulnerable to the force, shock, and after eiects of the explosion of the mine.

Another object of this invention is the provision of a vessel of compliant construction which can enclose and transport a volume of water comparable in shape and dimensions to the water displaced by a conventional ship, as a means of simulating the passage of that ship, but which is much less susceptible to damage by hydrodynamic forces in general than other containers of such a volume of water.

Another object is the provision of such a structure which is relatively easy and inexpensive to construct, use, repair and to maintain in working order.

A further object is the provision of a structure of the type mentioned which is self-contained, which requires ICC the following description considered together with the accompanying drawing.

In the drawing:

FIG. 1 is a side elevational view of an embodiment of the invention.

FIG. 2 is a top plan v-iew of the embodiment.

FIG. 3 is a view of a portion of FIG. 1, on a larger scale, partly broken away.

FIG. 4 is a sectional view along the line 4-4 of FIG. 3.

FIG. 5 is a-sectional view along the line 5-5 of FIG. 3.

FIG. 6 is a sectional view along the line 6 6 of FIG. 3.

FIG. 7 is a sectional view along the line 7-7 of FIG. 1.

FIG. 8 is a sectional view along the line 8-8 of FIG. 1.

FIG. 9 is a sectional view along the line 9-9 of FIG. 8.

Referring to the drawing with more part-icularity the embodiment illustrated comprises an elongated frame structure of tubular members welded together and of a size to simulate the size of `a target vessel, that is, a vessel which would be destroyed by its movement over a mine. The design of the skeletal `frame vstructure includes longitudinal members 11, struts 12 and braces 13 of tubular construction and such as to provide a .series of longitudinal-recesses 14 in these parts adapted to be submerged in the lbody of water (see FIG. 4); Thus, a star shaped cross sectional configuration may be lused. In the drawing, a six pointed star shaped cross section is illustrated and disposed with a diametrically opposite pair of ends 15, 15 of the star in a vertical longitudinal plane while the other points of the star 16, 16 and 17, 17 lie in two parallel horizontal planes, the upper of these planes being at the Water level. Y

The tubular members are welded together so that interiors of the members are continuous within sections delineated Iby bulkheads 18. (See FIG. 6.) The interior spaces t-hus provided are filled with a liquid, such as water 19, which may contain such agents yas -rust inhibitors, freezing point depressants, dyes, etc. Filling tubes 20, with removable closure caps21 are connected at convenient points above the water level to facilitate placing liquid in the spaces. Standpipes 22 with removable caps 23 may also be provided at convenient points to permit pumping water from the tubular sections through a flexible hose (not shown) inserted to 4a selected level.

The forward end of the structure having the star-shaped cross section is attached to a bow section 24 which displaces water in a conventional manner and contains the driving and steering mechanisms including the engine 29, screw 25 and rudder 26 usually placed at the stern of the ship. Also, a conventional bridge 27, anchor 28, and crew and supply quarters are included in the bow.

The structure is maintained afloat by a series of buoyant cells 30 the number being in excess of that required so as to furnish a factor of safety in the event of damage. Each of these cells comprises an inner heavy rubber pneumatic container 31 an intermediate protective lining 32 of heavy exible porous fabric having a smooth inner surface and an outer cage 33. The cage 33 is preferably of wire-rope net in the shape of a longitudinally split cylinder, the split ends being flanged at 34 so that they can be conveniently opened and closed. The anges are secured together by bolts 35. The cage 33 is set in place by welding it to the upper longitudinal frame members 11 which are positioned for purpose of support within the horizontal plane delineated by the points of the star 16, 16 but at interval positions within the star configuration such that the buoyant forces acting on the cells 30 will be transmitted directly to the other members of the framework. The pneumatic containers are equipped each with a conventional check valve 36 for filling with air and adjusting internal pressure. A constant pressure may be maintained by a central source of compressed air and a conventional regulator (not shown) pneumatically connected to the valves 36 in any conventional manner.

Cat walks 37 may also be secured to the structure, as shown, to facilitate inspection, maintenance, repair of the structure, and replacement of the inner pneumatic containers 31.

The sides of the submerged portion of the structure are provided with panels 38, pairs of which are attached cantileverwise by cleats 39 of the longitudinal members 11, the cleats serving additionally to stiften the longitudinal members. The opposite ends of a pair of panels extends to a midway point between adjacent longitudinal members 11, thereby collectively delineating a submerged surface comparable to that of a target vessel. The panels are retained in this normal position by resilient cables 40 attached by clamps 41 and which extend transversely with some tension across each pair of panels and which are slidably engaged with sleeves 42. These sleeves 42 are integral with the panels. Thus, the panels 38 are swingably openable against the resilient action of the cables 40 and are normally held thereby in the closed position. The panels 38 are of a stiff flexibly resilient material, such as that used in the manufacture of conveyor belts. This provides a compliant envelope structure capable of retaining a shape comparable to that of a target Vessel under normal operating conditions and yet yieldable under the forces of shock waves and surges that pass through the body of water into which it is submerged and which may be generated by a mine explosion or other transient conditions.

Alternatively, the structure may be modified from that illustrated in the drawing by forming the panels as single mperforate members between consecutive longitudinal members 11, 11. Suitable imperforate panels for such alternative construction comprises any of the conventional flexible or inflexible sheets of material, such as sheet metal, fabric, rubber, plywood, etc.

Iclaim:

1. A pressure mine sweeper comprising an open truss structure of interconnected tubular members, buoyant means for floating the structure in a body of water, panel sections covering and surrounding the truss structure where it extends below the water surface, said panel sections being resiliently openable, and means for moving the structure through the body of water, said covering sections collectively simulating the physical shape of a target Vessel, said truss structure having recessed sides and the panel sections extending across said recesses.

2. A pressure mine sweeper comprising an open truss structure of interconnected tubular members, buoyant means for floating the structure in a body of water, panel sections covering and surrounding the truss structure where it extends below the water surface, said panel sections being resiliently openable, means for moving the structure through the body of water, said covering sections collectively simulating the physical shape of a target vessel, said tubular structural members being filled with a liquid providing increased shock resistance to the truss structure and effecting reserve buoyancy and corrosion control.

3. A pressure mine sweeper as defined by claim 2 in which the interior of the tubular members are intercommunicated to form a continuous interior space, means for filling the space with a liquid and means for withdrawing the liquid from the space.

4. A pressure mine sweeper as defined by claim 1 in which the panel sections normally extend across the recesses, each panel section being held in normal position by resiliently yieldable cables connected to the structure across said recesses, said cables being yieldable under forces produced by underwater explosion, sea action, or maneuvering of the mine sweeper, but resistant to pressure developed against the sections by movement of the structure through the water under normal operating conditions.

5. A pressure mine sweeper as defined by claim 4 in which the panel sections have transverse loop portions slidably engaging the resiliently yieldable cables.

6. A pressure mine sweeper as defined by claim 1 in which the cross sectional configuration of the structure is in the general shape of a multi-pointed star.

7. A pressure mine sweeper as defined by claim 6 in which the configuration is of the form of a six pointed star and the buoyant means are disposed relative to the Vstructure to result in a pair of opposite points of the star lying in a vertical longitudinal plane and the other four apexes lying in two parallel horizontal planes.

References Cited UNITED STATES PATENTS 602,912 4/ 1898 MccGwire 114--68 1,297,558 3/1919 Gray 114--68 3,012,534 12/ 1961 Thomas 114--235 MILTON BUCHLER, Primary Examiner. T. M. BLIX, Assistant Examiner. 

1. A PRESSURE MINE SWEEPER COMPRISING AN OPEN TRUSS STRUCTURE OF INTERCONNECTED TUBULAR MEMBERS, BUOYANT MEANS FOR FLOATING THE STRUCTURE IN A BODY OF WATER, PANEL SECTIONS COVERING AND SURROUNDING THE TRUSS STRUCTURE WHERE IT EXTENDS BELOW THE WATER SURFACE, SAID PANEL SECTIONS BEING RESILIENTLY OPENABLE, AND MEANS FOR MOVING THE STRUCTURE THROUGH THE BODY OF WATER, SAID COVERING SECTIONS COLLECTIVELY SIMULATING THE PHYSICAL SHAPE OF A TARGET VESSEL, SAID TRUSS STRUCTURE HAVING RECESSED SIDES AND THE PANEL SECTIONS EXTENDING ACROSS SAID RECESSES, 